That is a shame. How do they judge what will be "important" 20, 50 or 100 years from now? Historians now use things such as early 20th century catalogs to study the changing needs of the times. I doubt the publishers realized what value they would have. I wonder what kind of footage it is that the BBC is destroying?
I'm not 100% sure, But I think it includes Quiz Shows, Game Shows, Weekday shows aimed at women, weekday kiddie shows, stuff like that. They may keep examples, but one or two episodes is hardly enough, considering that a weekday cooking show can provide facinating insight into how people ate.